Rock-drill.



PATBNTED AUG. 2, 1904.

F. L. WHITBHEAD.

ROCK DRILL.

APPLIOATION FILED JULY 14, 1903.

2 SHBETS-SHEET 1.

N0 MODEL.

IN VEN 70.? 1 5-66101 iv/1' fi/zife/mad A TOR/V5 Y5 WITNESSES- h CLM PATENTED AUG. 2, 1904.

F. L. WHITBHEAD.

ROCK DRILL.

APPLICATION FILED JULY 14, 1903.

2 SHEETS-3531 2.

N0 MODEL.

W/ TNESSES UNITED STATES Patented AugustIQ, 1904.

PATENT OFFICE.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 766,564, dated August 2, 1904,

Application filed ly 14, 1903.

To (1. 117mm if 'nm l concern:

Be it known that 1, FREDERICK LYMAN 'urrnnmo, a citizen of the United States, and a resident of Butte, in the county of Silverbow and State of Montana, haveinvented a new and Improved Rock-Drill, of which the following is a full, clear, and exact description.

This invention relates to improvements in rock-drills of the type in which the drill is moved in its operating direction by hammerblows; and one of the objects is to so construct the device as to utilize a portion of the driving force of the hammer to turn the drill and keep the cutting edge at a certain distance from the bottom of the hole.

Other objects of the invention will appear in the general description.

I will describe a rock-drill embodying my invention and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure l is a side elevation of a rock-drill embodying my invention. Fig. 2 is a section on the line )1 w of Fig. 3. Fig. 3is asection on the line ,1 w of Fig. 2. Fig. 4 is a section on the line 1/ 1 of Fig. 2. Fig. 5 is a section on the line of Fig. 2, and Fig. 6 shows the drill in operating position.

Referring to the drawings, 1 designates the supporting guide-bar for the drill mechanism, and this guide is adjustable as to its angle on a jack-bar arm 2. Movable along the guidebar is a carriage comprising a tubular body 3, having arms 4 5 extended from one side, said arms having at their ends return members 6 for engaging against the outer sides of the ribs T of the guide-bar. The side of the guidebar adjacent to the carriage 3 is provided with a rack 8, between any pair of teeth of which a pawl 9 is designed to engage. This pawl 9 is attached to a block 10, movable in the arm 1, which is made tubular, and it is pressed outward by means of a spring 11. An upwardly and outwardly inclined lug 12 extends from the block through a slot in the upper wall of the tubular arm 4:, the purpose of which will hereinafter be described.

Serial No. 165,420. (No model.)

Movable in the tubular carriage 3 is a tube 13, through which the drill let passes. ()n the upper end of the tube 13 is a collar 15, having at one side a tapped hole to receive the screw-threaded portion of a yoke-like clutch member 16, and at the opposite side is a threaded hole to receive the clamping-bolt 17.

On the lower end of the tube 13 is a collar 18, supporting a clutch member 19, similar to the clutch member 16, and also supporting the clamping thumb-screw 20. Arranged between the collar 15 and the upper endof the carriage is a spring 21 for moving the drill in its upward or outward direction. A tappet-rod 22 is carried by the tube 13 and is designed to engage with the lug 12 to release the pawl from the rack 8. As here shown, this tappetrod is secured in place by means of the adjustable clutch member 16.

The outer surface of the tube 13 is provided with spirally-arranged ratchet-teeth 23 24:, (see Fig. 5,) the spirals being extended in opposite directions, the bearing-surfaces of the teeth of both sets being on the same side, so that the tube is rotated constantly in one direction during its reciprocating movements. At one end of the tubular carriage 3 are opposite pawls 25 26 for engaging with the ratchet-teeth 23, and at the opposite end of the carriage are opposite pawls 27 28 for engaging with the teeth 2%. These pawls are mounted to slidein tubular projections 29, and they are pressed inward by means of springs 30, surrounding the stems of the pawls and engaging at the outer ends with threaded collars 31, arranged in the ends of the tubular projections. By. this arrangement during the operative movement of the drill it will be turned by means of the pawls 27 28, and on the reverse movement under the influence of the spring 21 the drill will be continued in rotation by the pawls 25 26 engaging with the teeth 23.

It will be noted that the pawls of a pair operate alternately that is, in engagement with the shoulder portion of a tooth the opposite pawl of said pair will ride over the space between the teeth, so as to engage an under tooth and continue the movement. By this arrangement a quick rotary movement is provided, and the drill will turn on a very short stroke.

In the operation, as before stated, the drill is moved in operative direction by the blows of a hammer and is returned by means of the spring 21. As the drill cuts deeper in the rock its stroke becomes longer until the tappet-rod 22 engages with the lug 12, which forces the pawl 9 out of engagement with the rack 8, permitting the carriage to move down one notch on the guide-rail. The carriage may be quickly drawn back to its normal or starting position by manually forcing the pawl out of engagement with the rack, and obviously when necessary for cleaning or the like the carriage may be wholly removed from the guide-bar. Further, it will be seen that by the clutch devices the drill can be quickly changed without moving the carriage. The guide can be adjusted to any angle up or down, and the ratchet-teeth on the tube 13 can be made so as to turn on their forward or back stroke, or both, depending upon the direction of the ratchet-teeth. As a hole becomes deeper the stroke of the drill increases and turns more on each stroke, and thus the cutting-point of the drill will not strike twice in the same place.

Having thus described my invention,1 claim as new and desire to secure by Letters Patent 1. A rock-drill comprising a guide, a carriage movable along said guide, a drill-carrying tube movable in the carriage, and means for imparting rotary motion to said tube while moving back and forth, the said rotary motion being at all times in the same direction, and the said means causing the degree of rotary motion to increase with the increasing length of drill-strokes.

2. A rock-drill comprising a guide, a carriage adjustable along said guide and having a tubular body portion, a drill-carrying tube movable through said tubular portion of the carriage, the said tube having oppositely-disposed spiral ratchet-teeth, and spring-pressed pawls mounted in the carriage and engaging with said teeth.

3. A rock-drill comprising a support, a carriage mounted on said support and having a tubular body portion, a drill-carrying tube movable in said body portion, a spring for moving said tube in one direction, the said tube having on its outer surface oppositelydisposed ratchet-teeth, the said teeth having a spiral trend, opposite spring-pressed pawls mounted in the carriage for engaging with the teeth of one series, and oppositely-dis posed spring-pressed pawls mounted in the carriage for engaging teeth of the other series, the pawls of a pair being arranged to operate alternately.

4:. A rock-drill comprising a guide-bar having a rack, a carriage movable along the guide-bar, a spring-pressed pawl mounted in the carriage for engaging with said rack, a drill-carrying tube movable in the carriage and having exterior oppositely disposed ratchet-teeth which have a spiral trend, pawls in the carriage for engaging with said teeth, and a tappet-rod carried by said tube for movingthe first-named pawl out of engagement with the rack.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FREDERIGK LYMAN WHITEHEAD.

Witnesses:

FRANK E. WHITEHEAD, GEORGE W. IRVIN. 

